At first I thought this was Leucozona lucorum on the basis of its brown scutellum. However closer scrutiny revealed that the front two long veins on the wings meet before they reach the wing-edge, which is characteristic of Volucella pellucens (Complete British Insects, M. Chinery, Collins, 2005, page 312). My guess is that vein pattern is less subject to intraspecific variability than scutellum colour, so I will go with the identification as Volucella pellucens.

Photos taken in Reading University grounds, Reading, UK, on 2009-06-11.